RESUMEN
OBJECTIVES: Purpose of the present study was to compare external root resorption (ERR) volumetrically in maxillary incisors induced by orthodontic treatment using self-ligating brackets (Damon Q, DQ) or conventional brackets (Titanium Orthos, TO) with the help of cone-beam computed tomography (CBCT). PATIENTS AND METHODS: A sample of 32 subjects, with Angle Class I malocclusion and anterior crowding of 4-10â¯mm, was divided randomly into two groups: a DQ group, in which self-ligating DQ brackets with Damon archwires were used; and a TO group, in which conventional TO brackets with large Orthos archwires were applied. The study was conducted using CBCT scans taken before (T1), and near the end (9 months after the initiation of treatment; T2) of the orthodontic treatment. The extent of ERR was determined volumetrically using Mimics software. Changes in root volume were evaluated by repeated-measures analysis of variance as well as by paired and independent t-tests. RESULTS: While significant differences were found between T1 and T2 for root volume in both groups (pâ¯< 0.05), there was no difference between the groups regarding the amount (mm3 or relative change) of ERR (pâ¯> 0.05). Maxillary central and lateral incisors showed similar volume loss (pâ¯> 0.05). Furthermore, the TO group showed a higher prevalence of palatinal and proximal slanted RR compared with the DQ group (pâ¯< 0.05). CONCLUSIONS: It is not possible to suggest superiority of one bracket system over the other only considering root resorption pattern or amount. Higher incidence of slanted RR found in patients treated with the TO system warrants further research to identify possible specific causes.